They went to understand the origins of rice in China and to date a specific cave site. What the archeologists discovered was that ancient hunter-gatherers may have been pottery-makers as well, indicating that they were more advanced than previously thought and that pottery originated in China. Israeli, Chinese and American teams, led by Bar-Ilan University's Elisabetta Boaretto, say they have succeeded in dating the fragments of a cone-shaped bowl excavated in the 1990s in a small cave in China's Hunan province. Early last week, the team reported that they had reexcavated the site and, using the most well-preserved ceramic fragments, been able to date the bowl to about 18,000 years ago. The bowl, which is about 25 cm. in diameter at its widest point, is the oldest known ceramic work. Because pottery-making is not usually associated with hunter-gatherers, who foraged to eat and did not domesticate wild animals or plant food, the archeologists were surprised by their findings. "This is a change of a paradigm using a very early primitive ceramic," Steve Weiner, director of the Kimmel Center for Archeological Science at the Rehovot-based Weizmann Institute of Science, told The Jerusalem Post on Wednesday. Boaretto and Weiner - the Israeli segment of the group - contributed the technical know-how to the process. Weiner's expertise is in mineralogy and site layering, Boaretto's in radiocarbon dating and fieldwork. Boaretto, who is currently under contract with the Kimmel Center, was on a flight from Hawaii and was not available for comment. Radiocarbon dating is difficult because it may not be entirely accurate. Critics say excavated fragments also contain minerals that skew the results. However, Weiner said that by screening out the best samples, the team had succeeded in cleaning and dating the fragments properly. According to an article by Andrew Lawler in ScienceNOW, some scholars are confused about the dating. Because other civilized technologies surfaced in different parts of Asia long before pottery-making did, he says, the question is why pottery-making developed in China first. Other experts, such as Yosef Garfinkel, a professor of archeology at the Hebrew University of Jerusalem, are optimistic about the team's findings. Garfinkel said Wednesday that the significance of the dating of this 18,000year-old bowl lay in the question of when pottery started. It is generally accepted that Israeli pottery is 8,000 years old, Syrian pottery is 9,000 years old and Japanese pottery - which used to be considered the oldest - is 12,000 years old. But now, it appears that Chinese pottery is even older. Logically, said Garfinkel, this makes sense. China had a more developed civilization, and pottery-making could very well have spread from China to Korea to Japan. And although Weiner stressed that nothing was certain, he said the dating of the bowl represented a different lifestyle for hunter-gatherers than archeologists have always attributed to them, and that was a pleasant surprise. "Discovering it was so old was unexpected," said Weiner. "That wasn't what we had in mind."